UNIVERSITY   OF    CALIFORNIA 

COLLEGE   OF    AGRICULTURE 

AGRICULTURAL    EXPERIMENT   STATION 

BERKELEY,    CALIFORNIA 


A  METHOD  OF  DETERMINING  THE 

CLEAN  WEIGHTS  OF  INDIVIDUAL 

FLEECES  OF  WOOL 


J.  F.  WILSON 


BULLETIN  447 

January,  1928 


UNIVERSITY  OF  CALIFORNIA  PRINTING  OFFICE 

BERKELEY,  CALIFORNIA 

1928 


A  METHOD  OF  DETERMINING  THE  CLEAN  WEIGHTS 
OF  INDIVIDUAL  FLEECES  OF  WOOL 

J.  F.  WILSON* 


INTRODUCTION 

The  desirability  of  placing  the  fleece  weights  of  sheep  on  a  clean 
basis  has  been  recognized  by  sheep  breeders  and  wool  specialists.  The 
shrinkage  of  wool,  and  consequently  the  grease  weight  of  the  fleece, 
varies  with  the  breed  of  sheep,  the  individuality  of  the  animal,  its 
care  and  management  during  the  period  of  growth  of  the  fleece, 
seasonal  variation,  the  length  of  the  fleece,  climatic  and  soil  conditions 
under  which  the  sheep  are  run,  and  moisture  content.  Wool  may 
vary  in  shrinkage  from  about  30  per  cent  to  about  80  per  cent.  It  is 
obviously  fallacious,  therefore,  to  compare  the  fleece  weights  of  indi- 
viduals of  the  same  breed  or  of  individuals  of  different  breeds,  unless 
the  fleece  weights  are  on  a  clean  basis. 

Data  from  the  wool  laboratory  of  the  University  of  California2 
show  that  sheep  of  the  same  breed,  kept  together  in  the  same  fields 
during  the  entire  period  of  fleece  growth,  may  vary  as  much  as  10  per 
cent  in  shrinkage.  Such  a  difference  means  that  a  fleece  weighing 
12  pounds  and  having  a  60-per-cent  shrink  yields  the  same  amount 
of  clean  wool  as  a  fleece  weighing  16  pounds  and  shrinking  70  per 
cent.  Yet  most  breeders  would  consider  a  fine-wool  ewe  producing  a 
12-pound  fleece  a  light  shearer,  but  would  consider  the  ewe  producing 
a  16-pound  fleece  of  grease  wool  entirely  satisfactory. 

Practically  all  standard  texts  used  in  teaching  animal  husbandry 
laud  certain  breeds  on  account  of  their  heavy  wool  production,  while 
other  breeds  are  criticized  as  being  light  shearers.  To  quote  from  one 
modern  text:  "The  American  Merino  as  a  wool  producer  is  famous. 
No  class  of  sheep  shears  ....  so  heavy  a  fleece.  Many  mature  females 
shear  from  12  to  15  pounds."  The  same  text,  in  discussing  the  Shrop- 
shire breed,  states  "Coffey  gives  the  average  weight  of  fleece  at  8  to 
10  pounds."  These  weights  are  all  on  a  grease  basis  and  the  reader 
of  the  text  is  led  to  infer  that  the  comparison  of  fleece  weights  of  the 
two  breeds  is  a  direct  one.     It  is  possible  that  if  the  fleeces  of  the 

1  Assistant  Professor  of  Animal  Husbandry  and  Associate  Animal  Husband- 
man in  the  Experiment  Station. 

2  Advanced  registry  records. 


4  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

American  Merinos  and  Shropshires  were  scoured,  the  difference  in  the 
shrinkage  of  the  two  breeds  under  similar  conditions  would  be  the 
difference  between  65  per  cent  and  48  per  cent.  Assuming  these 
figures  of  fleece  weights  and  of  shrinkages  to  be  approximately  correct, 
the  clean  weight  of  the  American  Merino  fleeces  would  be  4.20  to 
5.25  pounds,  while  the  Shropshire  fleeces  would  weigh  4.16  to  5.20 
pounds,  or  practically  the  same  as  the  Merino. 

The  idea  of  establishing  an  advanced  registry  for  fine-wool  sheep 
was  suggested  by  Miller,3  after  a  conference  with  W.  T.  Ritch,  an 
Australian  wool  expert  who  was  visiting  at  this  station. 

In  California  an  advanced  registry  of  Rambouillet  sheep  is  main- 
tained at  the  present  time  as  an  activity  of  the  California  Branch, 
American  Rambouillet  Breeders'  Association.  The  rules  and  regu- 
lations governing  the  admittance  of  animals  to  advanced  registry  were 
developed  by  the  writer  in  conference  with  Rambouillet  breeders. 
These  rules  require  ewes  to  shear  a  minimum  of  5.25  pounds  and 
rams  a  minimum  of  7.7  pounds  of  clean  or  scoured  wool  in  twelve 
months'  growth.  The  work  incident  to  the  inauguration  of  this 
advanced  registry  for  sheep  necessitated  devising  a  means  of  obtaining 
clean  weights  of  fleeces.  This  publication  attempts  to  describe  the 
procedure,  which  has  been  evolved  by  the  trial  method. 

Within  the  past  three  or  four  years,  states  other  than  California 
have  manifested  interest  in  advanced  registry  of  sheep.  Several 
agricultural  colleges,  too,  have  evinced  a  desire  for  information  as  to 
how  properly  to  scour  small  samples  of  wool.  It  is  hoped  that  this 
publication  will  answer  the  questions  relative  to  experimental  wool 
scouring  and  serve  as  a  guide  to  those  interested  in  the  subject;  also 
that  it  may  lead  to  placing  comparative  fleece  weights  on  a  scoured 
or  clean  basis,  the  only  basis  upon  which  real  progress  in  breeding 
for  heavy  wool  production  can  be  made. 


THE   PROBLEM   OF   EXPERIMENTAL  SCOURING    OF   WOOL4 

Experimental  wool  scouring  should  be  undertaken  with  a  view  of 
eliminating,  insofar  as  is  possible,  experimental  error.  The  methods 
employed  by  most  commercial  scouring  plants,  in  which  no  attempt 


3  Miller,  Robert  F.  Advanced  registry  for  fine  wooled  sheep.  Natl.  Wool 
Grower  8(l):38-40.     1918. 

4  Wool-scouring  work  has  been  carried  on  by  several  stations,  notably  those 
of  Wyoming  and  Texas,  and  by  the  United  States  Department  of  Agriculture 
at  Beltsville,  Md.  However,  the  methods  employed  at  these  and  at  other 
stations,  in  obtaining  the  clean  weights  of  individual  fleeces,  differ  from  the 
method  described  in  this  paper.  They  are  either  small  commercial-type  plants 
or  else  do  not  provide  for  obtaining  a  homogeneous  sample  of  the  entire  fleece 
for  the  scouring  operation. 


BUL.  447]         DETERMINING   CLEAN  WEIGHTS  OF  FLEECES  OF  WOOL  5 

is  made  to  put  the  work  on  a  standard-moisture  basis,  are  obviously 
unfitted  for  experimental  purposes.  Furthermore,  in  commercial  wool 
scouring',  it  is  not  always  customary  to  try  to  remove  all  of  the  foreign 
matter  in  the  wool,  but  only  a  sufficient  quantity  to  allow  the  stock  to 
work  well  in  subsequent  manufacturing  processes.  Especially  is  this 
true  of  plants  which  offer  scoured  wools  for  sale.  In  experimental 
work,  on  the  other  hand,  the  method  employed  should  be  one  which 
will  remove  all  of  the  dirt  and  all  of  the  yolk  except  that  which  is  a 
component  part  of  the  fiber  itself.  In  other  words,  if  two  identical 
lots  of  wool  were  to  be  scoured,  one  commercially  and  one  experi- 
mentally, the  latter  should  have  the  higher  shrinkage,  if  any  variation 
in  results  appears. 


FIRST  ATTEMPTS   AT  SAMPLE   SCOURING   AT  THE    UNIVERSITY 

OF   CALIFORNIA 

An  almost  complete  absence  of  printed  literature  descriptive  of 
scouring  small  quantities  of  wool  necessitated  the  gradual  evolution 
of  the  method  herein  described.  At  first  it  was  decided  to  scour  whole 
fleeces.  A  wooden  vat  was  constructed  in  a  manner  which  simulated 
the  three-bowl  scouring  machinery  used  in  commercial  plants.  Baskets 
made  of  hardware  cloth  were  constructed  to  fit  tightly  inside  each  of 
the  three  'bowls'  so  that  after  the  wool  had  been  scoured  the  entire 
mass  could  be  lifted  out  without  losing  any  of  the  wool.  This  method 
was  wholly  unsatisfactory.  The  amount  of  wool  in  the  volume  of 
scouring  solution  was  so  large  as  to  prevent  free  movement  of  the 
stock  through  the  solution,  a  cardinal  principle  in  scouring  wool.  Yet 
had  the  capacity  of  the  tubs  been  increased  to  permit  free  movement 
of  the  stock,  the  time  required  to  heat  the  water  to  the  desired  tem- 
perature would  have  made  progress  very  slow  and  the  cost  of  all 
operations  relatively  high.  Furthermore,  it  was  found  that  a  large 
fleece,  when  wet,  was  so  heavy  that  two  men  were  required  to  lift  it 
from  the  tubs. 

Determining  the  clean  weight  of  a  fleece  by  scouring  samples  was 
then  undertaken.  A  representative  sample  was  obtained  by  spreading 
the  fleece  out,  weather  end  up,  on  an  Australian  type  of  skirter7s  table. 
The  fleece  was  sorted  into  back,  shoulder-sides-and-neck,  belly,  britch, 
tags,  and  pieces.  Each  of  these  sorts  was  weighed  in  grams,  and  the 
percentage  of  the  entire  fleece  which  each  sort  represented  was  calcu- 
lated. A  500-gram  sample  was  then  made  up,  containing  the  same 
percentage  of  each  sort  as  was  contained  in  the  whole  fleece.     For 


6  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

instance,  if  the  belly  constituted  5  per  cent  of  the  weight  of  the  fleece, 
then  25  grams  of  belly  wool  was  put  into  the  500-gram  sample.  The 
shrinkage  of  the  sample  was  taken  as  the  shrinkage  of  the  fleece  and 
the  clean  weight  was  calculated. 

This  method  greatly  reduced  the  amount  of  hard  manual  labor 
involved  and  permitted  more  than  one  test  on  each  fleece.  However, 
the  time  required  to  sort  the  fleece  and  to  make  up  representative 
samples  was  so  great  that  only  one  or  two  fleeces  could  be  tested  in 
eight  hours  and  the  large  number  of  weighings  and  calculations 
involved  increased  the  possibility  of  error. 

A  further  disadvantage  lay  in  the  fact  that  so  much  manual 
manipulation  of  the  fleece  caused  some  of  the  dirt  to  be  lost,  and  this 
affected  the  results.  Had  the  loss  been  evenly  distributed,  the  error 
would  not  have  been  serious,  but  it  is  obvious  that  those  sorts  which 
normally  contain  the  bulk  of  loose  dirt,  namely  the  back  and  britch, 
lose  in  manipulation  a  larger  proportion  of  their  weight  than  do  the 
shoulder  or  neck.  The  scoured  product  obtained  by  this  method  was 
fairly  satisfactory. 

It  was  realized  that  if  the  fleece  could  be  thoroughly  mixed  up  into 
a  homogeneous  mass,  samples  of  any  convenient  amount  could  be 
taken  at  random,  any  one  of  which  would,  theoretically,  represent  the 
fleece.  Attempts  were  made  to  mix  the  fleece  by  hand,  by  breaking  it 
into  small  locks  and  then  turning  this  mass  over  repeatedly  with  a 
silage  fork,  but  this  plan  proved  too  laborious. 

THE    UNIVERSITY    OF    CALIFORNIA    METHOD    FOR    EXPERIMENTAL 

SCOURING    OF    WOOL 

The  method  of  experimental  scouring  now  used  has  been  tested 
thoroughly.  Its  accuracy,  simplicity,  and  economy  indicate  that  the 
principles  involved  in  its  operation  might  be  adopted  by  experiment 
stations  at  which  wool-scouring  work  is  contemplated.  The  following 
equipment  is  involved : 

(a)  A  means  for  heating  water  directly  in  the  scouring  tubs. 
Temperature  of  the  bath  must  be  initially  the  same  for  each  lot  of 
wool,  otherwise  the  results  will  not  be  comparable.  Several  samples 
may  be  scoured  in  each  tub  before  replacement  of  the  scouring  solu- 
tion is  necessary,  hence  it  is  advisable  to  use  either  direct  injection  of 
live  steam  into  the  tubs  or  to  provide  gas  burners  which  will  permit 
reheating  the  bath  to  the  desired  temperature.  Of  these  two  methods, 
the  gas  is  preferable  since  direct  injection  of  steam  dilutes  the  bath 
with  condensation. 


BuL.  447]        DETERMINING  CLEAN  WEIGHTS  OF  FLEECES  OF  WOOL 


Fig.  1. — Fleece  breaker.     This  machine  breaks  up  the  fleece  into  small  locks 
<  and  makes  it  into  a  practically  homogeneous  mass  preparatory  to  scouring. 


Fig.  2. — Interior  construction  of  the  fleece  breaker.  The  lower  cylinder 
housing  is  made  of  hardware  cloth  on  a  wooden  frame  and  is  hinged  so  that  it 
can  be  dropped  down  for  cleaning  out  the  machine.  Dirt  removed  by  the  action 
of  the  cylinder  passes  through  this  lower  housing  and  falls  into  the  drawer  below, 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


%' teeth.  e*aa 
/£" projection 


Fig.  3. — Detail  of  breaker  cylinder.     A,  top  view;  B,  view  of  large  end. 


BUL.  447]         DETERMINING  CLEAN  WEIGHTS  OF  FLEECES  OF  WOOL  9 

(b)  Balances.  A  balance  with  a  capacity  of  20  kilograms  and  a 
sensibility  of  one  or  two  grams  is  sufficiently  accurate  for  determining 
the  grease  weight  of  the  fleece.  An  additional  balance  with  a  capacity 
of  from  200  to  500  grams  and  sensibility  of  one  centigram  should  be 
used  for  weighing  out  the  samples  before  and  after  scouring. 


Screen  rT-ome 

Fig.  4. — Details  of  top  and  bottom  cylinder  housing. 

(c)  A  device  for  mixing  the  wool  thoroughly  and  opening  the  tip, 
or  weather  end,  so  that  the  scouring  liquor  may  permeate  the  stock 
quickly  and  evenly.  For  this  purpose  a  machine  embodying  the  prin- 
ciple of  the  cone-type  duster  used  in  many  commercial  plants  has  been 
designed  and  built  at  the  wool  laboratory  of  this  institution.  The 
construction  of  the  machine  is  so  simple  that  it  may  be  easily  built  by 
a  carpenter  and  the  metal  parts  required  are  all  standard.  Its  cost 
need  not  exceed  $100.00,  including  a  % -horsepower  motor.  For  wools 
coarser  than  %  blood,  the  dimensions  of  the  breaker  should  be 
increased;  otherwise  the  long  fibers  will  have  a  tendency  to  become 
wrapped  around  the  small  end  of  the  breaker  cone.  Figures  1,  2,  3, 
and  4  show  the  detailed  construction  of  the  apparatus. 


10  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

(d)  Four  medium-sized  galvanized-iron  wash  tubs.   Three  of  these 
are  used  to  hold  the  scouring  liquors  and  the  fourth  contains  the  rinse. 

(e)  One    small    galvanized-iron    tub    with    galvanized    fly-screen 
bottom  (fig.  5). 

(/)   A  heavy  commercial  laundry  wringer  (fig.  6). 
(g)   A  wooden  paddle  about  two  feet  long  for  agitation  of  the  wool 
in  the  scouring  solution  (fig.  5). 

(h)   A  device  for  drying  the  scoured  wool  (fig.  7). 


Fig.  5. — Tubs  used  in  scouring  the  samples.  The  bottom  of  one  of  the  tubs 
has  been  replaced  by  galvanized  fly  screening.  This  tub  fits  inside  each  of  the 
others  during  the  scouring  process  and  is  used  to  lift  the  sample  from  the  scouring 
solutions. 

(i)  An  oven  in  which  the  bone-dry  weight  of  the  scoured  wool 
may  be  obtained,  or  a  room  so  located  or  constructed  that  the  humidity 
and  temperature  remain  practically  constant.  It  is  not  necessary  to 
standardize  the  conditions  under  which  the  grease  weight  of  the  fleece 
is  obtained,  since  fluctuations  in  grease  weight  due  to  atmospheric 
changes  are  merely  reflected  in  greater  or  less  shrinkage.  It  is  abso- 
lutely essential,  however,  that  the  scoured  wool  be  weighed  under 
constant  or  controlled  conditions.  The  Emerson  textile-conditioning 
oven  has  been  found  satisfactory  for  this  purpose.  If  neither  the 
conditioning  oven  nor  the  constant  temperature  and  humidity  room 
is  available,  scoured  samples  may  be  stored  in  any  convenient  room, 


BUL.  447]         DETERMINING  CLEAN  WEIGHTS  OF  FLEECES  OF  WOOL 


11 


Fig.  6. — Type  of  wringer  found  satisfactory  for  scouring  small  samples  of  wool. 


Fig.  7. — The  wool  dryer;  an  adaptation  of  the  sirocco-type  blower, 
The  air-heating  device  is  not  shown. 


preferably  in  a  basement,  and  weighed  at  such  times  as  a  sling 
psychrometer  indicates  a  certain  humidity.  Such  an  arrangement  is 
satisfactory  only  if  the  fluctuation  in  humidity  is  comparatively  small, 
on  account  of  the  'lag.' 


12  UNIVERSITY   OF    CALIFORNIA EXPERIMENT    STATION 


METHOD   OF   PROCEDURE 

1.  The  fleece  is  first  weighed  in  grams.  Heavy  dung  locks,  shanks, 
twine,  and  other  foreign  material  should  be  weighed  back  and  the 
total  subtracted  from  the  gross  grease  weight.  These  'offs'  do  not 
properly  belong  in  the  fleece.  Ordinary  tags  and  sweat  locks  may  be 
separated  out  and  the  entire  quantity  scoured  separately.  The  clean 
weight  of  these  is  added  to  the  clean  weight  of  the  fleece.  The  fleece 
is  then  fed  through  the  "breaker"  and  the  weight  again  taken.  The 
difference  represents  shrinkage  due  to  loss  of  dirt ;  the  loss,  expressed 
in  per  cent,  is  later  used  to  calculate  what  the  original  grease  weight 
of  the  samples  would  be  had  they  not  been  fed  through  the  machine. 
It  is  advisable  to  put  the  wool  through  the  breaker  two  or  three  times 
in  order  to  mix  it  thoroughly. 

2.  Three  samples  are  then  made  up  by  extracting  from  various 
parts  of  the  basket  enough  small  bits  of  wool  to  make  up  the  amount 
desired.  While  it  is  obviously  unnecessary  to  use  exactly  100  or  200 
grams,  such  an  amount  saves  record  keeping  and  also  facilitates 
calculations  of  yields  and  shrinkages. 

3.  Seven  gallons  of  water  and  about  60  grams  of  soda  ash  are  added 
to  each  of  three  tubs  and  the  temperature  of  the  solution  is  raised  to 
125°  F. 

4.  Neutral  soap,  such  as  is  used  in  commercial  plants,  should  be 
used.  This  soap  in  solid  form  comes  in  barrels.  While  most  wool 
scourers  prefer  the  coconut-oil  soap,  that  made  from  cottonseed  oil  is 
usually  cheaper  and  will  also  be  found  satisfactory.  The  soap  in  the 
solid  form  should  not  be  added  to  the  tubs,  owing  to  the  fact  that  small 
bits  may  not  dissolve  readily  and  may  get  into  the  wool.  About  two 
pounds  of  the  solid  soap  should  be  placed  in  a.  three-gallon  pail  and 
about  two  gallons  of  water  added.  The  soap  is  then  heated  and  stirred 
until  it  has  completely  dissolved.  A  large  beaker  or  dipper  may  be 
used  to  transfer  this  soap  stock  to  the  tubs. 

There  is  no  definite  unit  of  measure  of  the  correct  amount  of  soap 
for  the  scouring  bath.  Weighing  the  solid  soap  accurately  is  of  no 
avail,  since  its  moisture  content  varies  greatly,  especially  after  long 
storage.  Insufficient  soap  fails  properly  to  cleanse  the  wool,  while  too 
great  a  quantity  will  cause  the  wool  to  become  ropy  and  partially  to 
felt.  Felting  of  the  wool  prevents  effectual  penetration  of  the  scouring 
liquor.  The  best  indication  of  the  optimum  amount  of  soap  in  the 
scouring  bath  is  the  appearance  at  the  time  the  wool  is  passed  through 
the  wringer.  Best  results  will  be  secured  when  soap  bubbles  appear 
freely  but  disappear  quickly  as  the  wool  is  being  fed  through  the 


BUL.  447]         DETERMINING  CLEAN  WEIGHTS  OF  FLEECES  OF  WOOL  13 

rollers.     If  the  bubbles  are  copious  and  tend  to  linger  on  the  wool 
when  the  wringer  is  stopped,  the  bath  contains  too  much  soap. 

For  work  in  connection  with  experimentation  involving  the  scour- 
ing of  many  samples,  all  of  the  soap  stock  should  be  made  up  at  one 
time.  One  or  more  samples  of  wool  not  involved  in  the  project  may 
first  be  scoured  in  order  to  ascertain  the  correct  amount  of  soap.  If 
the  soap  solution  is  made  up  at  such  a  concentration  that  it  is  gela- 
tinous at  room  temperature,  between  450  and  500  grams  of  the  liquid 
soap  will  probably  be  found  correct  for  each  tub. 

5.  A  tub  one  size  smaller  than  those  containing  the  scouring  bath 
is  used  to  hold  the  100-gram  sample  of  wool.  The  small  tub  should 
have  the  bottom  replaced  by  galvanized  fly  screening  (fig.  4).  This 
tub,  containing  the  wool,  is  immersed  in  one  of  the  larger  tubs.  The 
wool  is  stirred  gently  with  the  wooden  paddle.  After  from  two  to 
four  minutes'  immersion  the  smaller  tub  is  lifted  out  of  the  bath,  and 
the  wool  is  put  through  the  wringer.  It  is  then  replaced  in  the 
screen-bottomed  tub,  which  is  now  immersed  in  the  second  tub.  This 
operation  is  carried  on  three  times,  after  which  the  sample  is  rinsed 
in  the  fourth  tub  which  contains  only  water  heated  to  about  85°  F. 
After  thoroughly  rinsing,  the  wool  is  placed  in  the  dryer. 

6.  The  dryer  should  be  operated  at  not  over  160°  F.  Wet  wool 
dried  at  temperatures  higher  than  160°  F  may  become  yellow,  harsh, 
and  brittle.5  The  dryer  should  provide  as  rapid  a  current  of  warm 
air  as  it  is  possible  to  obtain,  if  quick  drying  is  desired.  Sun  drying 
is  not  as  satisfactory  as  artificial  drying,  on  account  of  the  greater 
length  of  time  required  and  also  because  of  the  danger  of  losing  small 
particles  of  wool  and  the  possibility  of  dust  and  other  foreign  matter 
getting  into  the  samples. 

7.  After  the  samples  have  been  reduced  to  air  dryness  they  should 
be  transferred  to  the  conditioning  oven  where,  after  about  one  hour 
at  220°  F,  the  bone-dry  weight  may  be  taken  and  the  normal  weight, 
based  on  the  standard  regain,  calculated.  If  weights  are  to  be  taken 
in  a  constant  temperature  and  humidity  room,  the  samples  should  be 
allowed  to  regain  for  at  least  24  hours,  and  preferably  two  or  three 
days,  before  weighing. 

8.  After  weighing  the  scoured  samples,  the  yield  of  each  is  calcu- 
lated and  the  average  yield  of  the  three  samples  is  taken  as  the  yield 
of  the  entire  fleece.  The  following  notes,  taken  from  the  University 
of  California  records,  illustrate  the  way  in  which  the  data  are  kept. 

A  variation  of  more  than  1.5  per  cent  in  the  yield  of  any  set  of 
three  samples  warrants  repetition  of  the  work. 

s  International  Library  of  Technology  79  (Section  12)  : 8.  International  Text- 
book Co.,  Scranton,  Pennsylvania. 


14 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


RECORD  OF  WEIGHINGS  FOR  CALCULATING  THE 
SCOURED  WEIGHT  OF  A  FLEECE 


Sheep  No U.  C.  402 

Breed Rambouillet. 

Owner U.  of  C 


Date  sheared 3-24-2 

Days  of  growth 212 

Length  of  staple  (inches)... .1 .87 

grams  grams 

Gross  grease  wt 6,722 Gross  machine  wt 6,327. 


Wt.  of  basket 2,112 Wt.  of  basket 2,112. 

(a)  Net  grease  wt 4,610 (6)  Net  machine  wt 4,215. 

(c)  Loss  in  machine  (a-b) 895 grams 

(d)  Per  cent  loss  in  machine  (     -  ) 8.57. 


(i) 


SCOURING  RECORD  OF  SAMPLES 


Sample 
No. 

(e) 

Grease 

weight 

in  grams 

(/) 

Calculated 

original 

grease  weight 

eXIOO 

100%-d 

in  grams 

(?) 

Scoured 

weight 

bone-dry 

in  grams 

(h) 

Conditioned 

weight 

<7X1.16 

in  grams 

ii) 
Yield 

yXlOO 

in  per  cent 

1 

200 

218.74 

76.68 

88.94 

40.66 

2 

200 

218.74 

77.12 

89.45 

40.81 

3 

200 

218.74 

76.42.... 

88.64 

40.52 

Total 121.99 

(j)  Average  yield,  per  cent 40-66 

(k)    Calculated  clean  wt.  of  fleece,  less  tags  (  aX~ —  ) 1 ,874 grams 

(0     Clean  wt.  of  tags  (bone  dry  wt.Xl.16) 56 grams 

(m)  Calculated  total  clean  wt.  of  fleece  (k  plus  I) 1 ,930 grams 

(n)    Calculated  total  clean  wt.  of  fleece  (k  plus  I) 4-25 pounds 

Work  done  by /.  F.  Wilson Date  finished 7-ll-'27 


BUL.  447]         DETERMINING  CLEAN  WEIGHTS  OF  FLEECES  OF  WOOL  15 


ADVANTAGES   OF   THE   CALIFORNIA    METHOD 

While  this  method  of  obtaining  from  small  samples  the  shrinkage 
of  an  entire  fleece  leaves  much  to  be  desired,  it  has,  nevertheless, 
certain  advantages.  First  and  chief  among  these  is  the  fact  that  if 
mistakes  are  made  subsequent  to  obtaining  the  net  grease  weight  of 
the  fleece,  neAv  samples  may  be  obtained  from  the  same  fleece  and  the 
work  repeated.  Where  whole  fleeces  are  scoured,  any  error  in  weights 
or  in  scouring  technique  permanently  vitiates  the  results.  Second, 
there  is  no  possibility  of  losing  even  small  quantities  of  wool  except 
through  carelessness.  Third,  the  method  is  simple.  Fourth,  it  requires 
relatively  small  quantities  of  all  supplies  used  in  scouring.  Fifth,  if 
the  work  is  properly  done,  the  scoured  stock  will  be  cleaner  and  more 
attractive  than  that  turned  out  by  most  commercial  plants. 


RESULTS   OF  WOOL-SCOURING   TESTS6 

In  order  to  test  the  efficiency  of  the  method  described  in  the  fore- 
going pages,  a  series  of  trials  was  concluded  in  the  wool  laboratory 
of  the  California  Agricultural  Experiment  Station.  The  wool  used 
was  all  California  middle-counties  fine,  practically  free.  It  was  of 
about  six  months'  growth  and  was  taken  from  purebred  Rambouillet 
wethers.  Four  fleeces  were  mixed  by  hand  and  the  mixture  was  then 
twice  put  through  the  fleece  breaker  in  order  to  insure  as  nearly  a 
homogeneous  stock  as  possible.  One-hundred  gram  samples  were  then 
made  up  from  this  machined  wool.  The  shrinkage  figures  in  the 
following  tables  do  not  take  into  account  the  dirt  removed  by  the 
machine,  since  the  object  of  the  work  was  merely  to  determine  what 
differences,  if  any,  were  due  to  various  conditions  imposed  on  the  wool. 

Differences  in  weight  due  to  variable  atmospheric  conditions  were 
overcome  by  weighing  all  of  the  samples  of  any  one  experiment  during 
a  single  hour;  that  is,  all  of  the  clean  weights  listed  in  table  1  were 
taken  during  the  same  hour.  The  clean  weights  shown  in  table  2  were 
likewise  taken  during  a  single  hour,  although  not  during  the  same 
hour  as  were  those  in  table  1.  In  any  one  test,  therefore,  the  results 
are  strictly  comparable,  but  the  shrinkages  of  table  1  are  not  neces- 
sarily comparable  with  those  of  subsequent  tables.  The  importance 
of  taking  into  consideration  the  percentage  of  saturation*  of  the  air 
may  be  illustrated  by  the  fact  that  the  samples  used  in  one  series 
gained  about  1.5  grams  each  during  a  single  night. 

6  The  author  wishes  to  make  grateful  acknowledgment  to  Lowell  Clarke,  a 
student  who  performed  much  of  the  work  incident  to  the  data  presented. 


16 


UNIVERSITY   OF    CALIFORNIA EXPERIMENT    STATION 


Effect  of  the  Concentration  of  Soda  Ash. — Table  1  represents  an 
attempt  to  determine  the  differences  in  results  due  to  various  concen- 
trations of  soda  ash.    The  results  are  presented  in  tabular  form  below. 

Table  1  shows  practically  no  difference  in  shrinkages  obtained. 
Physical  examination  of  the  wool,  however,  revealed  a  greater  harsh- 
ness of  feeling  for  all  the  samples  above  and  including  Na  100  than 


TABLE  1 

Strength  of  Soda-ash  Solution 

(''Wyandotte"  soda  ash) 

(Temperature,  125°  F;  time  in  each  tub,  2  minutes) 


Sample 
No. 

Grams 

Soda  Ash 

for  each 

7  gals.  H20 

Strength  of 
solution- 
grams  per  liter 
Na2C03'+ 
NaaHCOs 

Grease 
weight 
samples 

Scoured 
weight 
samples 

Average 
yield  of 
samples 

Average 

shrinkage  of 

samples 

Na    20 
Na    40 
Na    60 
Na    80 
NalOO 
Nal50 
Na200 

20 

40 

60 

80 

100 

150 

200 

1.279    I 
1.850    I 
2.659 
3.192    I 
3.926    | 
5.592    I 
7.438    I 

grams 

100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 

grams 

50.41 
50.85 
49.96 
50.49 
51.20 
50.84 
50.57 
50.57 
50.65 
50.25 
51.58 
51.26 
50.72 
50.94 

per  cent 

50.63 
50.22 
51.02 
50.57 
50.45 
51.42 
50.83 

per  cent 

49.37 
49.78 
48.98 
49.43 
49.55 
48.58 
49.17 

prevailed  among  the  samples  from  Na  20  to  Na  60.  Samples  Na  100, 
Na  150,  and  Na  200  possessed  a  wiry  feeling  and  the  wool,  held  close 
to  the  ear,  did  not  have  the  proper  'drag.'  The  optimum  amount  of 
soda  ash  for  best  results  will  vary  with  the  degree  of  hardness  of  the 
water  used  and  with  the  type  of  wool  being  scoured.  At  Davis,  where 
these  tests  were  carried  on,  the  water  is  moderately  hard  (0.5208  gram 
NaHC03  per  liter)  and  a  solution  of  60  grams  of  soda  ash  to  7  gallons 
of  water  proved  most  satisfactory  for  all  ordinary  wools. 

Effect  of  the  Temperature  of  the  Scouring  Bath. — In  table  2  the 
only  variable  was  the  temperature  of  the  scouring  bath. 


BUL.  447]         DETERMINING  CLEAN  WEIGHTS  OF  FLEECES  OF  WOOL 


17 


While  the  average  shrinkages  obtained  vary  directly  with  the  tem- 
peratures at  which  the  wool  was  scoured,  it  is  apparent  from  a  study 
of  the  scoured  weight  of  the  samples,  that  the  probable  error  of  the 
average  shrinkage  is  high,  since  one  of  the  T  110  samples  had  exactly 
the  same  scoured  weight  as  one  of  the  T  150  samples.  As-  was  the 
case  with  series  A,  the  greatest  differences  here  were  noticeable  in  the 
physical  examination  of  the  scoured  wool.  Sample  T  110  was  lofty, 
soft,  and  open,  while  T  150  was  inclined  to  be  harsh  and  dry.  None 
of  the  wool,  however,  turned  yellow. 

TABLE  2 

Temperature  of  Scouring  Bath 
(60  grams  soda  ash  to  7  gals.  H20;  time,  2  minutes) 


Sample 
No. 

Temperature 
of  bath 

Grease 

weight 
samples 

Scoured 
weight 
samples 

Average 
yield  of 
samples 

Average 
shrinkage 

8  F 

grams 

grams 

per  cent 

per  cent 

T110 

no      1 

100 
100 

50.85 
50.90 

\      50.87 

49.13 

T125 

125        J 

100 
100 

50.55 
51.10 

|      50.82 

49.18 

T135 

135        I 

100 
100 

50.57 
50.92 

50.74 

49.26 

T150 

150        I 

100 
100 

50.85 
50.00 

|      50.42 

49.58 

A  temperature  of  125°  F  gives  good  results  with  most  wools  and 
has  an  advantage  in  that  the  operator  quickly  learns  to  tell  by  touch 
when  the  bath  is  approximately  125°  F.  This  temperature  is  about 
as  hot  as  the  hand  can  bear.  Exceptionally  heavy  wools  and  tags 
may  be  more  thoroughly  cleansed  at  from  135°  to  140°  F.  For  some 
types  of  wool,  better  results  may  be  secured  by  having  the  bath  in  the 
second  and  third  tubs  about  10  degrees  cooler  than  that  in  the  first  tub. 

Effect  of  the  Method  of  Agitation. — The  third  test  was  conducted 
to  determine  the  advisability  of  gently  stirring  the  wool  with  a  paddle 
during  its  two-minute  stay  in  each  of  the  three  tubs.  The  odd- 
numbered  samples  were  so  treated,  while  the  even-numbered  lots  were 
agitated  by  raising  and  lowering  the  small  screen-bottomed  tub  within 
the  larger  tubs  and  by  turning  it  at  the  same  time,  a  manipulation 
which  caused  considerable  agitation  of  the  scouring  liquor. 


18 


UNIVERSITY   OF    CALIFORNIA — EXPERIMENT    STATION 


TABLE  3 

Agitation  of  Wool  with  Wooden  Paddles 

(60  grams  soda  ash  to  7  gals.  H20;  temperature,  125°  F) 

Samples  scoured  in  numerical  order 


Wool  agitated  with  paddle 

Wool  agitated  by  manipulation  of  small  tub 

Sample 

No. 

Grease 
weight 

Scoured 
weight 

Shrinkage 

Sample 
No. 

Grease 
weight 

Scoured 
weight 

Shrinkage 

P  1 

grams 

100 
100 
100 
100 

grams 

50.52 
51.20 
51.00 
50.55 

per  cent 

49.48 
48.80 
49.00 
49.45 

P2 

grams 

100 
100 
100 
100 

grams 

51.64 
51.27 
51.74 
50.75 

per  cent 

48.36 

P  3 

P4 

48.73 

^k.0 

P  5 

P6 

48.26 

P  7 

P8 

49.25 

49.18 

Average.. 

48.65 

The  results  presented  in  table  3  are  fairly  consistent  and  show  that 
more  foreign  matter  was  removed  from  the  wool  by  the  slow  and 
gentle  action  of  the  wooden  paddle  than  was  removed  by  the  manipu- 
lation of  the  small  tub.  The  paddle,  properly  used,  takes  the  place 
of  the  'rakes'  in  the  commercial  scouring  plant.  All  of  the  samples 
stirred  gently  with  the  paddle  were  bright  and  open,  while  the  others 
were  decidedly  ropy. 

Effect  of  Using  the  Wringer. — Table  4  shows  the  desirability  of 
using  the  squeeze  rolls  or  wringer.  Odd-numbered  samples  were 
scoured  without  the  use  of  the  wringer.     After  twTo  minutes  in  each 


TABLE     4 

Use  of  Wringer  or  Squeeze  Kolls 

(60  grams  soda  ash  to  7  gals.  H20;  temperature,  125°  F;  time,  2  minutes) 

Samples  scoured  in  numerical  order 


Samples  not  passed  through  squeeze  rolls 

Samples  passed  through  squeeze  rolls 

Sample 
No. 

Grease 
weight 

Scoured 
weight 

Shrinkage 

Sample 
No. 

Grease 
weight 

Scoured 
weight 

Shrinkage 

Wl 

grams 

100 
100 
100 
100 

grams 

51.90 
52.18 
51.82 
51.62 

per  cent 

48.10 

47.82 
48.18 
48.38 

W2 

grams 

100 
100 
100 
100 

grams 

50.55 
51.20 
51.10 
50.85 

per  cent 

49.45 

W3 

W4 

48.80 

W5 

W6 

48.90 

W7 

W8 

49.15 

Average... 

48.12 

Average 

49.07 

BUL.  447]        DETERMINING  CLEAN  WEIGHTS  OF  FLEECES  OF  WOOL 


19 


bath,  the  sample  was  lifted  out,  allowed  to  drain  for  a  moment  and 
then  immersed  in  the  next  tub.  Even-numbered  samples  were  treated 
exactly  the  same  except  that  they  were  subjected  to  the  wringer  before 
passing  from  one  tub  to  the  next. 

The  data  presented  in  table  4  show  that  the  wringer  is  essential  to 
proper  scouring.  The  greatest  shrinkage  obtained  among  the  four 
samples  not  passed  through  the  wringer  is  less  than  the  lowest  shrink- 
age among  the  samples  on  which  the  wringer  was  used.  The  action 
of  the  'squeeze  rolls'  forces  the  water  out  of  the  wool  and  the  water 
carries  with  it  some  foreign  matter  which  otherwise  would  not  be 
removed.  Furthermore,  the  difference  in  the  appearance  of  the  odd- 
numbered  and  even-numbered  samples  was  very  striking.  Where  the 
wringer  was  used  the  wool  was  of  a  whiter  color  and  much  more  lofty 
than  were  the  samples  scoured  in  the  absence  of  the  'squeeze.' 

Effect  of  Scouring  Many  Samples  Consecutively  in  the  Same 
Solution. — Table  5  shows  that  many  samples  can  be  scoured  con- 
secutively in  the  same  solutions  without  materially  affecting  the 
results.  After  sample  33  had  been  scoured,  so  much  liquid  had  been 
removed  from  the  tubs  by  lifting  out  the  saturated  wool  that  it  was 
found  difficult  to  immerse  any  more  samples. 

Before  sample  33  (table  5)  was  scoured,  the  solution  in  the  first 
tub  had  become  heavily  impregnated  with  dirt.  Obviously  each  of 
the  other  two  tubs  contained  an  increasing  amount  of  sediment  as 
the  work  progressed.  Tests  of  the  scouring  solutions  were  made  at 
intervals  to  determine  the  percentage  of  sediment  in  the  bath. 
Samples  of  10  cc.  of  the  solution  were  centrifuged  for  six  minutes 
each.    The  results  are  showrn  in  graphic  form  in  figure  8. 


r 

I. 


flfi 

<jp 

i^^^ 

,,h4~ 

Seco 

nd  + 

'JO  tz 

'  /! 

Third  tUO'4        _ 

9        12       /3      fS      21      24     £7     30    33 
JXMPLE    NUMBER 


Fig.  8. — Percentage  of  sediment  in  scouring  solutions  (table  5), 


20 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


The  uniformity  of  results  shown  in  table  5,  despite  an  increasing 
sediment  content  in  all  three  tubs,  may  be  explained  by  the  fact  that 
the  sediment  has  a  tendency  to  settle  quickly  to  the  bottom  of  the  tub. 
The  screen  bottom  of  the  inner  tub  rests  about  an  inch  above  the  solid 


TABLE  5* 

Maximum  Number  of  Samples  Which  Can  Be  Effectively  Scoured  without 

Changing  the  Scouring  Solution 

(60  grams  soda  ash  to  7  gals.  H20;  temperature,  125°  F ;  time,  2  minutes) 

Grease  weight  of  samples  100  grams 


Sample  No. 

Shrinkage 

Sample  No. 

Shrinkage 

per  cent 

per  cent 

1 

46.21 

21 

45.62 

2 

45.42 

22 

45.58 

3 

44.96 

23 

45.80 

4 

45.48 

24 

45.98 

5 

45.41 

25 

46.12 

6 

45.41 

26 

46.08 

7 

45.38 

27 

45.23 

8 

45.78 

28 

45.42 

9 

46.19 

29 

45.68 

10 

46.14 

30 

45.50 

Average, 

Average, 

ltolO... 

45.638 

21  to  30 

45.701 

11 

46.14 

31 

45.67 

12 

45.36 

32 

45.18 

13 

45.95 

33 

45.13 

14 

45.35 

Average, 

15 

45.13 

31  to  33 

45.326 

16 

46.27 

17 

46.15 

18 

45.48 

19 

45.74 

20 

45.69 

Average, 

11  to  20 

45.726 

*  The  tests  reported  in  tables  5  and  6  were  conducted  with  a  different  lot  of  wool  from  that  used  in 
those  reported  in  tables  1  to  4  inclusive. 

bottom  of  the  tub  containing  the  scouring  bath.  Much  of  the  sediment, 
therefore  falls  through  the  screen  and  rests  on  the  bottom  of  the 
outer  tub,  where  it  is  not  in  contact  with  the  wool. 

Table  5  indicates  that  for  all  scouring  work  not  involving  extreme 
accuracy  of  results,  it  is  not  necessary  to  change  the  scouring  solutions 
often,  and  thus  a  considerable  saving  of  labor  and  material  is  effected. 


BuL.  447  J         DETERMINING  CLEAN  WEIGHTS  OF  FLEECES  OF  WOOL 


21 


Effect  of  the  Size  of  the  Sample. — The  amount  of  wool  selected  as 
a  representative  sample  should,  theoretically,  be  as  large  as  possible 
and  still  permit  efficient  work  and  comparative  ease  of  operation.  The 
trial  reported  in  table  6  was  carried  on  in  an  attempt  to  determine 
the  size  of  the  sample  which  should  be  used. 

TABLE  6 

Optimum  Size  of  Sample  for  Scouring 
(60  grams  soda  ash;  temperature,  125°  F;  time,  2  minutes) 


Sample 
No. 

Grease 

weight 

Scoured 
weight 

Shrinkage 

1 

grams 

100 

grams 

53.45 

per  cent 

46.55 

1A 

100 

53.55 

46.45 

2 

200 

107.30 

46.35 

2A 

200 

107.90 

46.05 

3 

300 

161.70 

46.10 

3A 

300 

162.50 

45.84 

4 

400 

216.45 

45.89 

4A 

400 

216.20 

45.96 

5 

500 

283.60 

43.28 

5A 

500 

277.95 

44.41 

6 

600 

327.55 

45.41 

6A 

600 

329.20 

45.14 

7 

700 

401.35 

42.67 

7A 

700 

394.65 

43.62 

8 

800 

453.70 

43.29 

8A 

800 

447.65 

44.05 

9 

900 

514.30 

42.86 

9A 

900 

507.15 

43.65 

10 

1000 

553.05 

44.70 

10A 

1000 

553.15 

44.69 

Table  6  indicates  that  with  the  equipment  previously  described, 
100-gram  samples  or  at  most  200-gram  samples  will  give  more  satis- 
factory results  than  samples  of  greater  weight.  The  tendency  in  this 
test  toward  a  general  decline  in  shrinkage  with  an  increase  in  weight 
of  samples,  indicates  that  less  foreign  matter  was  removed  when  the 
heavier  samples  were  used.  Furthermore,  the  variability  in  results 
tends  to  increase  with  the  weight  of  the  sample.  Since  samples  of 
about  200  grams  of  wool,  if  properly  extracted,  will  accurately 
represent  the  fleece,  and  are  easier  to  handle  than  any  larger  quantity, 
it  seems  logical  to  use  that  amount  in  determining  clean  weights  of 
fleeces. 


STATION  PUBLICATIONS  AVAILABLE   FOE  FEEE   DISTKIBUTION 


No. 
253. 

262. 

263. 
268. 
273. 


276. 
277. 
278. 
279. 
283. 
294. 
804. 

810. 
312. 
813. 

819. 
824. 

325. 


828. 
831. 
885. 

839. 

840. 

843. 
844. 

846. 
347. 

848. 
849. 

850. 

853. 
854. 
857. 


858. 

361. 

362. 
363. 

364. 

865. 
866. 

867. 

368. 


370. 
871. 


373. 
374. 


375. 
376. 


377. 
379. 


BULLETINS 
No. 


Irrigation  and  Soil  Conditions  in  the 
Sierra   Nevada   Foothills,   California. 

Citrus  Diseases  of  Florida  and  Cuba 
Compared  with   those   of   California. 

Size  Grades  for  Ripe  Olives. 

Growing  and  Grafting  Olive  Seedlings. 

Preliminary  Report  on  Kearney  Vine- 
yard Experimental  Drain,  Fresno 
County,   California. 

The  Pomegranate. 

Sudan   Grass. 

Grain    Sorghums. 

Irrigation  of  Rice  in   California. 

The  Olive  Insects  of  California. 

Bean  Culture  in   California. 

A  Study  of  the  Effects  of  Freezes  on 
Citrus   in    California. 

Plum    Pollination. 

Mariout  Barley. 

Pruning  Young  Deciduous  Fruit 
Trees. 

Caprifigs    and   Capriftcation. 

Storage  of  Perishable  Fruit  at  Freez- 
ing Temperatures. 

Rice  Irrigation  Measurements  and 
Experiments  in  Sacramento  Valley, 
1914-1919. 

Prune  Growing  in   California. 

Phylloxera-Resistant    Stocks. 

Cocoanut  Meal  as  a  Feed  for  Dairy 
Cows  and   Other  Livestock. 

The  Relative  Cost  of  Making  Logs 
from   Small  and  Large  Timber. 

Control  of  the  Pocket  Gopher  in 
California. 

Cheese    Pests    and   Their    Control. 

Cold  Storage  as  an  Aid  to  the  Mar- 
keting of  Plums. 

Almond    Pollination. 

The  Control  of  Red  Spiders  in  Decid 
uous  Orchards. 

Pruning  Young  Olive  Trees. 

A  Study  of  Sidedraft  and  Tractor 
Hitches. 

Agriculture  in  Cut-over  Redwood 
Lands. 

Bovine   Infectious   Abortion. 

Results  of  Rice  Experiments  in  1922. 

A  Self-mixing  Dusting  Machine  for 
Applying  Dry  Insecticides  and 
Fungicides. 

Black  Measles,  Water  Berries,  and 
Related  Vine  Troubles. 

Preliminary  Yield  Tables  for  Second 
Growth   Redwood. 

Dust  and  the  Tractor  Engine. 

The  Pruning  of  Citrus  Trees  in  Cali- 
fornia. 

Fungicidal  Dusts  for  the  Control  of 
Bunt. 

Avocado  Culture  in  California. 

Turkish  Tobacco  Culture,  Curing  and 
Marketing. 

Methods  of  Harvesting  and  Irrigation 
in  Relation  of  Mouldy  Walnuts. 

Bacterial  Decomposition  of  Olives  dur- 
ing Pickling. 

Comparison  of  Woods  for  Butter 
Boxes. 

Browning  of  Yellow  Newtown  Apples. 

The  Relative  Cost  of  Yarding  Small 
and   Large  Timber. 

Pear   Pollination. 

A  Survey  of  Orchard  Practices  in  the 
Citrus  Industry  of  Southern  Cali- 
fornia. 

Results  of  Rice  Experiments  at  Cor- 
tena,    1923. 

Sun-Drying  and  Dehydration  of  Wal 
nuts. 

The  Cold   Storage  of  Pears. 

Walnut  Culture  in  California. 


380. 

382. 

385. 
386. 

387. 
388. 

389. 
390. 

391. 

392. 
393. 
394. 

395. 
896. 

397. 

898. 
399. 


400. 
401. 

402. 
404. 
405. 
406. 
407. 


408. 
409. 


410. 
411. 
412. 

414. 

415. 
416. 

417. 

418. 

419. 

420. 

421. 
422. 

423. 

424. 

425. 
426. 

427. 

428. 

429. 


Growth  of  Eucalyptus  in  California 
Plantations. 

Pumping  for  Drainage  in  the  San 
Joaquin    Valley,    California. 

Pollination    of   the    Sweet   Cherry. 

Pruning  Bearing  Deciduous  Fruit 
Trees. 

Fig  Smut. 

The  Principles  and  Practice  of  Sun- 
drying  Fruit. 

Berseem  or   Egyptian   Clover. 

Harvesting  and  Packing  Grapes  in 
California. 

Machines  for  Coating  Seed  Wheat  with 
Copper   Carbonate   Dust. 

Fruit    Juice    Concentrates. 

Crop  Sequences  at  Davis. 

Cereal  Hay  Production  in  California. 
Feeding  Trials  with  Cereal  Hay. 

Bark  Diseases  of  Citrus  Trees. 

The  Mat  Bean  (Phaseolus  aconitifo 
lius). 

Manufacture  of  Roquefort  Type  Cheese 
from   Goat's  Milk. 

Orchard  Heating  in  California. 

The  Blackberry  Mite,  the  Cause  of 
Redberry  Disease  of  the  Himalaya 
Blackberry,    and   its   Control. 

The  Utilization  of  Surplus  Plums. 

Cost  of  Work  Horses  on  California 
Farms. 

The  Codling  Moth  in  Walnuts. 

The  Dehydration  of  Prunes. 

Citrus  Culture  in  Central  California. 

Stationary  Spray  Plants  in  California. 

Yield,  Stand  and  Volume  Tables  for 
White  Fir  in  the  California  Pine 
Region. 

Alternaria  Rot  of  Lemons. 

The  Digestibility  of  Certain  Fruit  By- 
products as  Determined  for  Rumi- 
nants. 

Factors  Affecting  the  Quality  of  Fresh 
Asparagus  after  it  is  Harvested. 

Paradichlorobenzene  as  a  Soil  Fumi- 
gant. 

A  Study  of  the  Relative  Values  of  Cer- 
tain Root  Crops  and  Salmon  Oil  as 
Sources  of  Vitamin  A  for  Poultry. 

Planting  and  Thinning  Distances  for 
Deciduous  Fruit  Trees. 

The  Tractor  on  California  Farms. 

Culture  of  the  Oriental  Persimmon 
in   California. 

Poultry  Feeding:  Principles  and 
Practice. 

A  Study  of  Various  Rations  for 
Finishing  Range  Calves  as  Baby 
Beeves. 

Economic  Aspects  of  the  Cantaloupe 
Industry. 

Rice  and  Rice  By-products  as  Feeds 
for   Fattening   Swine. 

Beef   Cattle   Feeding  Trials,    1921-24. 

Cost  of  Producing  Almonds  in  Cali- 
fornia; a  Progress  Report. 

Apricots  (Series  on  California  Crops 
and  Prices). 

The  Relation  of  Rate  of  Maturity  to 
Egg  Production. 

Apple   Growing  in   California. 

Apple  Pollination  Studies  in  Cali- 
fornia. 

The  Value  of  Orange  Pulp  for  Milk 
Production. 

The  Relation  of  Maturity  of  Cali- 
fornia Plums  to  Shipping  and 
Dessert   Quality. 

Economic  Status  of  the  Grape  Industry. 


CIRCULARS 

No.  No. 

87.  Alfalfa.  259. 

117.  The    Selection    and    Cost    of    a    Small  261. 

Pumping  Plant.  262. 

127.  House   Fumigation.  263. 

129.  The  Control  of  Citrus  Insects.  264. 
136.  Melilotus    indica    as    a    Green-Manure 

Crop  for  California.  265. 

144.  Oidium    or    Powdery    Mildew    of    the  266. 

Vine. 

157.  Control  of  the  Pear  Scab.  267. 
164.   Small  Fruit  Culture  in  California. 

166.  The  County  Farm  Bureau.  269. 

170.  Fertilizing    California     Soils    for    the  270. 

1918  Crop.  272. 
173.  The    Construction    of    the   Wood-Hoop 

Silo.  273. 

178.  The  Packing  of  Apples  in   California.  276. 

179.  Factors   of    Importance   in    Producing  277. 

Milk  of  Low  Bacterial  Count. 

202.  County   Organizations  for   Rural   Fire  278. 

Control. 

203.  Peat  as   a  Manure   Substitute.  279. 
209.  The  Function  of  the  Farm  Bureau. 

212.  Salvaging    Rain-Damaged    Prunes.  281. 
215.  Feeding  Dairy  Cows  in  California. 
217.  Methods   for  Marketing  Vegetables   in 

California.  282. 

230.  Testing  Milk,   Cream,   and   Skim  Milk 

for  Butterfat.  283. 

231.  The   Home   Vineyard.  284. 

232.  Harvesting    and    Handling    California  285. 

Cherries   for   Eastern    Shipment.  286. 

234.  Winter  Injury  to  Young  Walnut  Trees  287. 

during  1921-22.  288. 

238.  The  Apricot  in  California.  289. 

239.  Harvesting     and     Handling     Apricots  290. 

and  Plums  for  Eastern  Shipment.  291. 

240.  Harvesting    and    Handling    Pears    for 

Eastern  Shipment.  292. 

241.  Harvesting  and  Handling  Peaches  for  293. 

Eastern   Shipment.  294. 

243.  Marmalade  Juice  and  Jelly  Juice  from  295. 

Citrus  Fruits. 

244.  Central  Wire  Bracing  for  Fruit  Trees.  296. 

245.  Vine  Pruning  Systems. 

248.  Some   Common    Errors   in   Vine  Prun-  298. 

kig  and  Their  Remedies. 

249.  Replacing    Missing    Vines.  300. 

250.  Measurement   of   Irrigation   Water   on  301. 

the  Farm.  302. 

252.  Supports  for  Vines.  303. 

253.  Vineyard  Plans. 

254.  The  Use  of  Artificial  Light  to  Increase  304. 

Winter   Egg    Production.  305. 

255.  Leguminous  Plants  as  Organic  Fertil-  306. 

izer   in    California   Agriculture. 

256.  The   Control   of  Wild   Morning   Glory.  307. 

257.  The  Small-Seeded  Horse  Bean.  308. 

258.  Thinning  Deciduous   Fruits.  309. 


Pear  By-products. 

Sewing  Grain  Sacks. 

Cabbage  Growing  in  California. 

Tomato  Production  in  California. 

Preliminary      Essentials      to      Bovine 

Tuberculosis  Control. 
Plant  Disease  and   Pest  Control. 
Analyzing     the     Citrus     Orchard     by 

Means  of   Simple  Tree   Records. 
The  Tendency  of  Tractors  to  Rise  in 

Front;    Causes  and   Remedies. 
An  Orchard  Brush  Burner. 
A  Farm  Septic  Tank. 
California  Farm  Tenancy  and  Methods 

of  Leasing. 
Saving  the  Gophered  Citrus  Tree. 
Home  Canning. 
Head,   Cane,   and   Cordon   Pruning  of 

Vines. 
Olive  Pickling  in  Mediterranean  Coun- 
tries. 
The  Preparation  and  Refining  of  Olive 

Oil  in   Southern   Europe. 
The  Results  of  a  Survey  to  Determine 

the  Cost  of  Producing  Beef  in  Cali- 
fornia. 
Prevention  of  Insect  Attack  on  Stored 

Grain. 
Fertilizing  Citrus  Trees  in  California. 
The  Almond  in   California. 
Sweet  Potato  Production  in  California. 
Milk  Houses  for  California  Dairies. 
Potato   Production   in   California. 
Phylloxera  Resistant  Vineyards. 
Oak  Fungus  in  Orchard  Trees. 
The  Tangier  Pea. 
Blackhead  and   Other  Causes  of  Loss 

of  Turkeys  in  California. 
Alkali  Soils. 

The   Basis  of   Grape   Standardization. 
Propagation   of  Deciduous   Fruits. 
The   Growing  and   Handling  of  Head 

Lettuce  in   California. 
Control     of     the     California     Ground 

Squirrel. 
The    Possibilities    and    Limitations    of 

Cooperative  Marketing. 
Coccidiosis  of  Chickens. 
Buckeye  Poisoning  of  the  Honey  Bee. 
The  Sugar  Beet  in  California. 
A  Promising  Remedy  for  Black  Measles 

of  the  Vine. 
Drainage  on  the  Farm. 
Liming  the  Soil. 
A  General  Purpose  Soil  Auger  and  its 

Use  on  the  Farm. 
American   Foulbrood   and  its   Control. 
Cantaloupe  Production  in  California. 
Fruit  Tree  and  Orchard  Judging. 


The  publications  listed  above  may  be  had  by  addressing 

College  of  Agriculture, 

University  of  California, 

Berkeley,  California 

9m-3,'28 


